1. Field of the Invention
The present invention relates to a method of manufacture and devices for constructing boxes and envelopes, and to an apparatus and method of fabricating and maintaining accurate register and feed on a printing press during the manufacture of various printed products, including, but not limited to, continuous form envelopes, boxes, business forms with integral pockets and/or attached envelopes, as well as a device for the imprinting, loading, forming and sealing of boxes and envelopes, while providing accurate registration during the entire fabrication process.
The registration devices and process described herein also enable a printing press to imprint graphics and data onto the underside of a continuous web of material without the use of a turn around devices commonly known as a turn bar. The devices for imprinting, loading, and sealing of envelopes enables the user to encode the outside of such envelopes with identifying information relating to the identity of the sender, such that the need for an enclosed identifying return payment coupon is thereby eliminated.
2. Description of Related Technology
Flat packaging pouches have grown in popularity in recent years, particularly in the field of direct mail advertising and related direct response "bang tab" envelopes. There is a large body of art pertaining to such envelopes for mailing, return reply, and advertisements with integral response mechanisms. It is obvious from the large body of prior art that numerous attempts have been made to correct the deficiencies or improve upon the features of each previous invention.
One common distinguishing feature in every cited reference in the art of envelope making, is the method of applying adhesive to one sheet or web and superimposing a second and separate sheet upon first web, thus resulting in a pouch. Such a method is described in U.S. Pat. No. 4,726,804, issued to Stitcher.
Stitcher describes a process in which a "U" shaped pattern of adhesive is deposited onto a bottom web, with the open end of the "U" corresponding to the open, or insertion, end of the finished pouch. A second web or sheet is superimposed over the first web, severed, and bonded to the "U" shaped adhesive, thereby forming a pouch. The resulting product can be folded or cut so as to form individual pouches (also referred to in the art as pockets) or left in a continuous roll form for automatic loading and imprinting prior to initial mailing.
The design deficiencies of a pouch envelope are well known in the industry. For example, the wider the resulting glue line, the larger the overall continuous envelope products must be in order to accommodate the particular correspondence or other item to be received in the envelopes. Consequently, the continuous envelope with a larger glue line will have larger dimensions than its counterpart conventional envelope which is folded and glued on its face so that the effective interior side of a conventional envelope is not affected.
The Stitcher reference also describes a method of feeding, cutting and attaching a second piece of material to a moving web to form the back of an envelope. The web is advanced by a pair of pull wheels which are driven synchronously together with the other driven rolls, and suitably controlled by known gear reducing methods, so that their surface speed matches the speed of the web in operation. Consequently, proper and precise indexing of the severed segments of the two webs may be accomplished.
Envelope manufacturing methods that combine two separate webs must make some provision for providing an extending flap. The Stitcher reference provides for the flap by die cutting and removing a section of waste material from the second web. This wasted material and the equipment needed to remove it can be cost prohibitive in practice. Thus, the Stitcher method requires the removal of a significant amount of waste material during the manufacturing process. Stitcher creates an amount of waste material that exactly matches the size of the envelope flap plus the size of the loading cutout. Stitcher applies the die cut portion to a moving bottom web with placement rollers that rotate at the same speed as the bottom web. Thus, Stitcher lays down a patch that is the same size as the envelope. Stitcher cuts the extra material and removes it from the web as waste. Stitcher does not address the problem of eliminating the wasted material. In order to vary the length of the applied patch, the second supply web must advance at a rate of speed different than that of the main web. Sticher makes no provisions for such a variable advance mechanism operating on the second web.
Some previous devices utilize a method of adhesively attaching each of the four sides of the pouch, thus requiring an alternative method of opening, as opposed to the traditional envelope flap being opened by a common letter opener. Such pouches contain printed instructional references on the outside of the envelope, directing the recipient to follow the proper sequence of steps required to remove portions in order to open said pouch. Many such envelopes provide a pull tab, tear strip, or snap off tab as the only "approved" method for opening the envelope. The use of the descriptor "approved" is remarkably important because, in actual use, pull tabs and tear strips routinely fail to tear fully along the intended length, and snap off tabs regularly fail to snap off along intended lines of weakness.
Having failed their intended purpose, the opening methods are rendered useless and the envelope recipient must resort to more primitive means to gain access to the envelope's contents. Most often, these primitive means include tearing the envelope apart along nonperforated lines of weakening. In many instances the enclosed materials are damaged, if not destroyed, because the envelope pouch tears in random and unpredictable directions.
A significant number of prior art return reply envelopes require that the return reply envelope be assembled by the recipient prior to mailing. If the return reply envelope has not already been destroyed in the process of opening the outer wrapper, then the recipient may attempt to assemble the reply vehicle, which, like the envelope opening instructions, requires the recipient to ignore conventional envelope construction methods and instead depend upon written and graphical instructions. Thus, the consumer is faced with the sometimes daunting task of deciphering the origami like diagrams and instructions describing the folding operations necessary to fold the device into a mailing vehicle.
U.S. Pat. No. 5,174,494, issued to Ashby is one example of the prior art in which the return envelope must be folded and formed by the recipient. The Ashby design prefers the use of transfer tape, instead of remoistenable adhesive, to aid the recipient in the attachment of the marginal edges of the envelope panels when forming the return envelope. Transfer tape requires the removal of a silicone impregnated release liner to expose the pressure sensitive adhesive, thereby creating disposal materials. Transfer tape is also far more costly than remoistenable adhesives. Since pressure sensitive adhesive remains active along its marginal edges after receiving a folded envelope panel, inserted materials that come in contact with the internal envelope seams will become immediately and most often, permanently attached inside the reply envelope.
Another problem for the recipients of such reply envelopes is the difficulty of properly inserting the reply payment coupon or ordering form such that the correct address is properly aligned in the die cut address window. Improper insertion of the coupon or order form will result in the U.S. Post Office's delivery of the envelope, with canceled postage, to the address shown in the window, namely, that of the original recipient, rather than that of the original sending organization. Misalignment of the coupon or order form can obscure relevant delivery address information, thereby resulting in significant delays in the delivery of the return envelope to the sending organization.
In addition to these operational disadvantages, flat packaging pouches have distinct and sometimes significant marketing disadvantages. First, because of their inherent design, flat pouches cannot hold bulky materials without creating undesirable "puckering". Puckering becomes a significant problem when the envelope must contain more than a single thickness of material or small parts. Second, because of the way inserted materials place stress on the "U" shaped seams, and more precisely the side seams, the flat pouch is less reliable as a containment device, a serious deficiency for those firms using envelope/pouches for parts packaging.
The "puckering" effect has two undesirable effects. First, the thicker the object placed within the pouch, the greater the stress placed on the bottom and side seams of the pouch. Second, in order to alleviate the problems associated with this added stress on side seams, pouch manufacturers have been forced to increase the overall size of the pouch, thereby creating an ever more significant problem with seam strength.
Upon insertion of materials into a pouch, the pouch deforms to relieve stress along the side seams, forcing the "opening" or insertion end of the pouch to reduce in size. The majority of the prior art references address the use of envelopes only for the purpose of sending a single, or at most, double thickness sheet of enclosed materials. However, present day billing and direct mailing techniques employ the use of multiple page insertions of advertisements. In fact, the current trend is toward a greater, not lesser, amount of enclosed matter in an effort to encourage purchases by the recipient of the advertised products or services.
In order to compensate for the puckering and reduced opening size problems, manufacturers have been forced to enlarge the overall dimensions of pouches, especially when compared to a comparable capacity gusseted or fold around envelope. In order to compensate for reduced seam strength, manufacturers have had to increase the width of the "U" shaped adhesive area.
However, enlarging a flat pouch package leads to a more undesirable problem, namely, ever increasing seam weakness. For example, a pouch with an interior dimension of 4".times.5" requires a seam width of approximately 1/8" on each side. The two side seams add 1/4" to the pouch, or 5.8% of the pouch's total width. When the pouch is enlarged to 8".times.10", the seam must be increased to at least 1/2" in order to maintain the same strength, thereby occupying 11.1% of total pouch width.
Gusseted and fold around envelopes offer distinct advantages over conventional envelopes or flat pouch design envelopes. Gusseted and fold around envelopes accommodate larger products while occupying a smaller planform area. In some cases, because the gusseted envelopes are formed with expandable side pleats, they can even replace small boxes as the packaging medium for a particular product. State of the art gusseted envelopes, produced by conventional envelope making methods have been available only in single piece form, only with pleats at the side and then only at significantly higher cost than comparable conventional envelopes. While flat pouch style envelopes have become available in continuous form tractor feed formats, gusseted and fold around envelopes have not. Also, the availability of gusseted envelopes is erratic because of the specialized machinery and techniques involved in fabricating the gusseted sides. Increased cost, a lack of a continuous form format, and regional unavailability have limited the appeal of gusseted envelopes to both manufacturing and direct mailing concerns. These same firms have been frustrated in their attempts to automate their packaging, printing and loading processes when a gusseted envelope design is needed for a particular application.
The gusseted envelope has the advantage of placing the stress created by the object residing within the envelope against the side and optional bottom pleats, rather than against a glued seam. The pleated gusset creates a "bellows" effect in the envelope, causing the perimeter, highly stressed areas to expand so as to reduce stress, thereby eliminating the problems of puckering, reduced opening size, and reduced seam strength.
A similar situation exists in box industry. Current designs of noncorrugated boxes used in the shipment of small parts are available only in single piece format. They are commonly referred to as either "folding" or "set up" boxes. Folding boxes are preformed, glued, and perforated by the box manufacturer. When used by the parts manufacturer, they are opened into full position by simultaneously squeezing against opposing sides of the box. This causes two flaps located in the bottom of the box to lock. Set up boxes, as the name implies, are completely set up by the box manufacturer before they are shipped. No assembly is required by the parts manufacturer. However, this design is considerably more costly to manufacture and ship, since the majority of the box shipment is by airplane. Not surprisingly, there already exists a large body of art which is directed to the making and erecting of boxes and envelopes. A brief summary of automated envelope and box making devices can be provided with reference to the following patented devices.
For example, U.S. Pat. No. 1,297,748, issued to Streeper, discloses the use of a form or mandrel around which a box is created.
U.S. Pat. No. 2,512,382, issued to Ringler, discloses another mandrel around which a flat blank is manipulated to form an interlocking, self supporting box structure.
In order to fold paper in a moving web, state of the art devices have traditionally relied on "plow folders." Similar in design to farm plows that "turn over" the earth, plow folders remain permanently fixed on the press and literally turn paper around. Plow folders are passive in design and have serious drawbacks. The first disadvantage is the generation of heat. Understandably, paper passing at high speeds through a plow folder generates a large amount of heat as well as wear. In addition, the plow folder places stress on the moving web, thereby increasing web tensions and creating potential stretching or breaking problems. Further, plow folders are not adjustable. Each new size of fold demands a separate folder. Nor does the plow folder design work well with multiple folds or pleats as are required in a gusseted design envelope. Finally, the frictional wear present in a plow folder creates additional web registration problems.
U.S. Pat. No. 4,915,679, issued to Gotou describes a process in which a multi-layered bag made from synthetic resinous film is pleated and joined to a kraft paper substrate. Gotou uses a combination of both plow and rotary folding devices. Gotou does not contemplate the severing and subsequent placement of a gusseted piece onto another web. Such an operation would require the pleating device to actually crease the web material so that it retains its pleating and shape once severed from the web. Without this permanent crease, the pleats would expand immediately after being severed from the web.
Gotou uses a stationary guide to deform and rotate the web material into a subsequent guide. Gotou is essentially a plow folder which generates a great deal of friction and heat and is susceptible to rapid wear. To counteract the web stresses caused by heat and friction, stationary plow folders are generally manufactured with wide gaps between the flair members and the remainder of the guide assembly. These wide gaps result in both low tolerance folding and radiused corners, rather than a tight crease. Tight tolerance plow folders are rarely used for long production requirements because they demand a tight fit between the flare and the guide members. This tight fit only magnifies the friction and heat problems inherent in such devices. Tight tolerance plow folders tend to jam more often and result in web stretching. Also, tight tolerance plow folders cannot handle a wide variety of web material thicknesses and must be manufactured for only a specific material thickness.
Gotou utilizes disk shaped flared members and forms the pleats having radiused corners in successive operations. The disadvantage of the Gotou method becomes apparent when operating a web at high tension. Web tension, such as experienced on an envelope press, will distort the partially formed folds produced by the Gotou multiple step process. Gotou does not address the problems of web stretching in between his roller folders.
An alternative design for creating a folding motion is to utilize an air bearing approach such as is used in a web reversal unit. However, air bearings are limited to a single fold per bar and are usually used to form large folds, such as in newspapers. The registration problems associated with web reverse units can also be a common problem with air bearing folders.
Some boxes or envelopes cannot withstand the demands placed on them without the use of some sort of adhesive. U.S. Pat. No. 3,626,819 discloses the use of a mandrel to form a box from a blank upon which an adhesive has been selectively applied.
U.S. Pat. No. 3,192,837, issued to Hoyrup et al., discloses a device in which the mandrel itself is heated so as to activate a heat sealable impregnated blank during the box forming process.
Another problem encountered in using a mandrel to form a box or envelope is the securing of the box to the mandrel during the temporary forming operation. U.S. Pat. No. 3,191,508, issued to Beamish, addresses the problem of box/mandrel contact by the use of vacuum ports within the mandrel die. The vacuum pressure permits the mandrel to grip the box during formation and allows rapid release of the box or envelope when the forming operation is completed.
The next step in the box envelope making art has been to attempt to integrate the various box forming operations into a single automated device. U.S. Pat. No. 3,635,129 discloses a machine for forming trays which incorporates a mandrel, hot melt adhesive, and vacuum ports within the mandrel to control manipulation of the blank stock.
U.S. Pat. No. 3,648,605, issued to Hottendorf, discloses a box making machine utilizing a mandrel, hot melt adhesive, and a vacuum. Similarly, U.S. Pat. No. 3,800,681, issued to Corderoy, discloses an automated device for fabricating cartons, which accomplishes a variety of folding operations with the assistance of mandrels, hot melt adhesives and vacuum ports.
An additional problem existing in the box making art has been the actual filling of a box during or immediately after the box fabrication step. U.S. Pat. No. 1,983,323, issued to Stokes, discloses a multiple step box making process including the step of filling the completed box with the desired product.
Another problem encountered in the box making art is registering or synchronizing a continuous web during the manufacturing process so that the box will be formed accurately and will receive printed information consistently on the box surface. U.S. Pat. No. 2,214,593, issued to Mustin et al., discloses the use of ink marks along the perimeter of the web which may be sensed by a photoelectric assembly.
U.S. Pat. No. 2,706,944, issued to Claff et al., discloses a machine for making blank boxes which incorporates the use of guide marks to a dummy web at predetermined spaced intervals in order to obtain a printed box blank.
U.S. Pat. No. 2,985,990, issued to Waite et al., discloses a web registration system using a series of apertures along the perimeter of the web material.
U.S. Pat. No. 3,185,046, issued to Gross, discloses the use of registration slots to position a blank accurately during the box forming process.
State of the art devices used to superimpose a piece part onto another substrate have utilized both "patching" units and "pick and place" units. Patching units are commonly used in the envelope trade to apply transparent "windows" to the inside of business envelopes. The patching unit cuts a predetermined length of "window" material from a continuous roll. Since exact window placement is of little consequence in envelopes, patching units are not well suited to the strict placement tolerances of gusseted envelopes. Also, most window envelope "patching" is done in sheet form, rather than on a high speed moving web.
Pick and place units, on the other hand, are designed to remove precut pressure sensitive materials from a silicone liner, and apply them to a moving web. Pick and place units are far more accurate than patching units, but require a drastic reduction in web speed. In addition, pick and place units are geared to the press, so they too have registration problems if the web is not in total synchronization with the finishing tools. Current state of the art patching and pick and place units neither monitor nor automatically adjust their operation in response to varying web registration. For example, if the web shifts, as is common during a press run, the press operator must either manually or, byway of an electrically controlled servo motor, move a splined worm gear either forward or backwards on the main drive shaft of the press. The exact amount of gear movement required to bring the patching and pick and place unit back into registration with the main web is speculative, depending solely on the experience and judgement of the press operator.
Thus, neither patching nor pick and place units can constantly monitor and then automatically advance or retard their operation as can the current invention. Driven by stepper motor and controlled by motion control logic, the nip and anvil roller of the current invention can momentarily increase or decrease its rate of rotation in order to "catch-up" or "fall back" to meet the changing state of the main web before transferring the piece part to the positioning roller and eventually the main web.
Patching and pick and place units can also become out of register with the main web because of gear wear and gear lash. Gear wear can result in a reduced diameter gear and thus, continuing to operate a patching or pick and place unit with worn gears will result in stack-up errors, where each additional piece part placed onto the moving web will be more and more out of register. Coupled with the problems resulting from web shift, gear wear can make registration all but unattainable. Gearing the pick and place unit to the press also dictates that the repeat cycling be fixed to a specific repeat length. The same is true regarding the registration of press printing stations and die-cutting stations.
Current flexographic presses require printing plates to be adhesively or magnetically mounted to a geared printing cylinder. The circumference of the printing cylinder and finishing dies must exactly match the repeat length of the desired finished printed piece. If, for example, the printed piece has a finished length of 31/2 inches, and the press utilizes a 1/8 inch circular pitch gearing system, the printing cylinder and dies must each be 28 teeth, or any number equally divisible by 28. Thus, the plate cylinder with mounted plate transfers an ink pattern of 31/2 inches in length to the moving web. Since the circumference of the 28 tooth plate cylinder is exactly 31/2 inches, the plate is required to repeat the same ink pattern every 31/2 inches. The same is true with the die repeat requirements.
The state of the art of flexographic printing press design requires that all print cylinders, dies, and nip rollers utilize gear drive trains. Therefore, geared print cylinders and dies must rotate at the speed of the press. To continue the above example, the above mentioned printing plate cannot, under the current technology, transfer a 31/2 inch pattern of ink to the web, lift off of the web, reduce its rate of rotation, skip the next 11 inch portion of web material, regain its original rate of speed, drop down to the moving web and then print another 31/2 inch pattern of ink upon the web.
In state of the art gear presses, because the cylinders and dies theoretically rotate at the same rate as the web, the above task would require a 116 tooth (14.5 inch circumference) print cylinder and die. The print cylinder and die would be manufactured with a 31/2 inch area of "live" matter and 11 inches of blank, wasted plate and tool steel, a significant underutilization of expensive material.
More important than the waste factor however, is the problem of maintaining web registration on a geared press. Even the most elementary training materials for press operators, such as Flexography Principles and Practice, 3d Edition (Copyright 1980, Flexographic Technical Association, Inc. 95 West 19 th Street, Huntington Station, N.Y. 11746) contain various passages warning of the potential for press misregistration:
"In order for registration to hold during the run, the proper tension must be set and maintained throughout the run. This is accomplished by adjusting the various tensions on the unwind, rewind, and nip rolls." (p. 28, col. 2 emphasis added) PA0 "Each color station has its own impression cylinder, and each station is driven through a gear train. It is very important that each gear in the gear train is manufactured to close tolerances, especially the tooth to tooth dimension since misregister can occur due to the inaccuracies of the driving gears. Since a number of gears are involved, it is possible that the error in only one gear can be magnified, causing the print register or print repeat to shift." (p. 76, col. 2 emphasis added) PA0 "Unwind tension control is necessary to print in good register. This is especially true on stack press equipment and just as true in respect to repeat variations on central impression cylinder presses." (p. 60, col. 1 emphasis added) PA0 ". . . overcoming core shaft inertia and gearing friction loads may take away all of the brake's sensitivity so it cannot control the web tension properly. Further, if the press speed is high and the core shaft and brake gearing have a high inertia value, as the roll decreases the brake may be turned to a zero setting and the tension value in the web can still be too high, thereby stretching the web in order to overcome high inertia value." (p. 60, col. 2 emphasis added)
It is important to note that this educational material not only informs the reader that web tension is critical to registration, but that gear tooth mesh tolerance and gearing friction loads also may have a detrimental impact on web registration. This warning takes on added significance when one considers the large number of gears on a typical printing press.
Not mentioned in the educational materials, but well known to those skilled in the art, is the problem of accurately determining the proper nip roller pressure to apply as the driving force to the web. Insufficient nip roller pressure results in web slippage and web shift, while excessive nip roller pressure deforms the nip roller, causing deflection and accelerated feed as the pliable nip roller covering resumes it former shape subsequent to compression.
Nip roll contact area varies with changes in the amount of pressure applied to the nip roller. For example, when under moderate pressure, a nip roller on a typical seven inch narrow web flexographic press, with average durometer value of ninety will contact an area of the web approximately one eighth of an inch by seven inches. That is a small contact area when considering the countervailing forces being exerted by the unwind and rewind rolls and explains why webs can slip and shift. The press operator can increase the nip roller pressure to obtain more contact area in an effort to stop slippage. Additional pressure applied to the nip roller can result in a contact area as much as one half inch by seven inches. However, the added contact area resulting from increase nip roller pressure does not come without substantial cost.
The additional pressure ultimately results in less contact area and significant nip roller expenses. This is because boosting nip roller pressures causes roller deflection. Roller deflection results in less contact area. And less contact area results in additional accelerated nip roller wear. Nip roller deflection is analogous to underinflated automobile tires. Underinflated tires have less tire to road contact area because the car's full weight is carried by the tire's outer edges, causing the center area of the tread to deflect away from the road. In nip rollers, high pressure applied to the roller's journal ends, causes the center of the roller to deflect away from the web. Thus, the nip roller has even less web contact area and just as with underinflated tires, high nip roll pressure causes premature wear, heat, and delamination resulting in unreliable web feed and excessive replacement costs.
High nip roller pressures also result in the accelerated feed of web material. At high pressures, the nip roller presses against the web and the opposing rotating roller, thereby compressing the roller's pliable outer covering. As the nip roller completes its rotation away from the midpoint of contact with the web, but while the nip roller is still in contact with the web, the pliable outer covering expands. The expansion actually powers the web at an accelerating rate of advancement which upsets web tensions.
The goal of the press operator is to adjust nip roller tension to the minimum amount required to achieve reliable web feed. However, since nip rollers are designed to pull material from the feed roll, and full feed rolls are quite heavy, a minimum nip roller tension setting will result in slippage when pulling material from a full feed roll. In actual operation, the press operator is constantly adjusting unwind and rewind tensions, nip roller tensions, plate to plate registration, and plate to die registration.
Some newer press designs have incorporated optical sensing devices that automatically track and adjust plate to plate printing discrepancies by way of monitoring printing registration marks in the margin of the web. These highly automated registration systems are expensive, available only on high end press models, and generally are not available for retrofit to existing press equipment. Numerous attempts have been made to provide for more exacting registration and feeding of web fed printing presses and imprinting devices.
The Indramat Division of The Rexroth Corporation, 255 Mittel Drive, Wood Dale, Ill. 60191 manufactures and sells digital intelligent AC servo drive motors for electronic line shafting applications and motion control software and electronics. FIG. 37 is a line art reproduction of FIG. 2 from an Indramat sales brochure no. IAE 74180 Rev A 09/93 entitled "Converting/printing machine with hybrid drive configuration," and depicts the state of the prior art relative to Indramat's approach to motion control on a converting/printing machine. As is typical of recent attempts to adapt motion control to existing gear type presses, Indramat shows in FIG. 37 a retrofit application where the infeed station 610 and printing sections 601 and 602 of a converting/printing machine are driven by one conventional main drive shaft 603 which is powered by motor 604 by way of drive belt 605. The finishing operations of die cutting station 606 and folding station 607 are driven by the company's intelligent servo motors 608 and 609. Indramat servo motors accept positioning signals from the motion control logic 611 and report back to the motion control logic 611 on the exact positioning of the servo motor shafts of servo motors 608 and 609. A position sensor 610 attached to the main drive shaft 603 provides a reference signal to the motion control logic 611 indicating the relative position of the printing press. The motion control logic 611 instructs the die cutting 608 and folding 609 servo motors to rotate, advance, or retard in direct relation to the position feedback sensor 610 attached to the main driveshaft 603.
In a departure from a hybrid approach of combining gear and servo technology, Indramat also offers sectionalized servo drives controlled by motion control logic, wherein each printing and web movement device is driven by an intelligent servo motor controlled by motion control logic, totally eliminating the need for a main drive motor, drive belt and main drive shaft. Each station is sectionalized, containing its own servo drive motor which both accepts and transmits positioning signals to and from the motion control logic.
Referring now to FIG. 38, which is a line art reproduction of FIG. 3 from an Indramat sales brochure no. IAE 74180 Rev A 09/93 entitled "Converting/printing machine with sectionalized drives," we see a depiction of a converting/printing machine controlled entirely by computer. Motion control logic 613-622 receives commands from computer 612. Thus, coordinated commands from computer 612 instruct each motion control logic 613-622 to direct each servo motor 628-632 to rotate, advance, and retard at a rate determined by the computer 612. Feedback positioning data is also generated by each servo motor 628-632 to provide monitoring capabilities to computer 612.
U.S. Pat. No. 5,050,812, issued to Mueller, discloses an envelope making machine containing register maintaining devices wherein pull rolls pull web material from a feed roll and maintain tension on said web by means of dancer rolls and pressure rollers. Proper feed rates are maintained by varying the rotation of an overfeeding clutch bearing. Dancer rolls are well known in the art and serve as either shock absorbers to take up slack in a web, or as active devices to force a web to advance or retard.
U.S. Pat. No. 5,016,182, issued to Bergland, et. al., discloses another method of register control by employing a dancer roll arrangement with a meter (nip) roll to pull the web material from a feed roll. The meter roll has an encoder (pulse generator) attached to its shaft, the encoder providing pulse signals to control the impression cylinder. The meter roll is driven by a variable ratio transmission attached to a servo motor power source by gears. Dancer rolls are employed to absorb web shocks. Bergland does not address any rewind tensioning issues because the final envelope product is sheeted from the end of the press into individual units, eliminating the need for rewind.
U.S. Pat. No. 4,984,458, issued to Montgomery, discloses a method of detecting printed register marks upon the web by way of photo optical sensing devices. Said sensing devices provide reference signals to a web tensioning device which provides a high pressure stream of air against the web and simultaneously applies power to variable clutch devices attached to the print cylinders.
U.S. Pat. No. 4,955,265, issued to Nakagawa, discloses a method of detecting printed or punched marks in the web by way of an optical sensor. A Hall Effect magnetic device attached to the end of a cutting cylinder provides reference pulses to the control logic, said control logic merging print location reference signals and cutting cylinder reference signals and transmitting appropriate "advance" or "retard" commands to a compensating roller, said compensating roller acting like a dancer roller to force an "advance" or "retard" condition upon said web.
U.S. Pat. No. 4,949,891, issued to Yamashita, provides register means by way of two separate gearing paths, an electromagnetic clutch and photoelectric tube, said photoelectric tube sensing printed marks on the back side of the web.
U.S. Pat. No. 4,913,049, issued to Sainio, discloses a process of using Bernoulli effect air techniques to diminish the "flutter" on a high speed web, said flutter disrupting the process of optically sensing printed register marks previously placed by ink methods upon said web. The invention utilizes the reference signals from optical sensors to vary the rate of air flow against the web to control varying rates of flutter.
U.S. Pat. No. 4,896,605, issued to Schroder, discloses a registration method by which a pulse generator is mechanically attached to a folding jaw cylinder. In addition, four brightness detecting sensors are permanently affixed to the printing press to monitor four distinctly separate zone groups. Said sensors establish a brightness value for each zone and transmit reference signals to the logic control circuitry, said logic control circuitry comparing said signals to the incoming pulse signals from the folding jaw cylinder. Web "advance" or "retard" commands are transmitted by said logic in the form of an increased or reduced voltage supply to a driving servo motor.
U.S. Pat. No. 4,892,426, issued to Steele, discloses a method of monitoring paper movement in printing devices such as cash registers and calculators. The invention employs rollers which engage the paper web along a flat surface, said rollers rotating about an axis at a rate matching the rate of paper flow into and out of the printer. Pulse generating devices are affixed to the shafts of said rollers, thereby providing a stream of input and output data to the control logic, where said data is compared and adjustments made accordingly.
U.S. Pat. No. 4,786,353, issued to Templeton, discloses a method of monitoring and controlling temperature on a plastic film web to control both repeat length and width variations.
U.S. Pat. No. 4,737,904, issued to Ominato, discloses a registration method where servo driven feed rollers with an attached pulse generator pulls web material from the feed roll. Pulses from said pulse generator merge at the control logic with reference signals obtained from photo optical sensors, said optical sensors detecting printed marks on the web. Advance or retard signals are sent to the feed roll servo motor to correct registration deficiencies.
U.S. Pat. No. 4,719,575, issued to Gnuechtel, provides print registration by analyzing areas of contrast changes on the printed web. Upon analyzing data from optical sensors used to detect the contrast areas, the control logic transmits commands to the press drive unit to "advance" or "retard" the web.
U.S. Pat. No. 4,533,269, issued to Pou, discloses a method for providing incremental advance of a supply web in a price marking tag and label device.
U.S. Pat. No. 4,552,608, issued to Hoffmann, discloses a computer controlled labeling machine wherein an encoder is affixed to the shaft of a cutter, said encoder providing reference signals to the feed roll stepper motor to feed the web stock. The control logic also receives reference signals from photo optical sensors, said sensors detecting printed register marks on the web of labels. Upon proper commands, the label web is cut into individual units. No rewind device is provided.
U.S. Pat. No. 4,541,335, issued to Tokuno, discloses a registration method wherein plate cylinders are driven by stepper motors, said stepper motors receiving pulse signals from the press control logic. Photo optical sensors detect "print start" marks on the web, thereby providing reference signals to the print cylinder stepper motors and the pull roller stepper motors, said pull rollers tending to pull web material from the feed roll. Two printing plates are mounted on each cylinder with a physical gap between said plates. Two impression cylinders are provided at each print station. Each print cylinder rotates to transfer the inked image from one plate to the web. A photo optical sensor detects "end print" register mark and the control logic commands the print cylinder to retard its rate of rotation while a predetermined length of the web passes without restriction through the gap between the mounted plates. The print cylinder, having received the appropriate "resume" commands from the control logic, returns to its original rate of rotation, thereby transferring the inked image from the second plate on the web currently entering the second said impression cylinder.
U.S. Pat. No. 4,528,630, issued to Sargent, provides print registration by way of printing a repeating series of marks on the web. Photo optical sensors detect the distance between said marks and provide reference signals to the control logic. Said control logic transmits "advance" or "retard" commands to servo motors affixed to the drive shaft gears at each print station.
U.S. Pat. No. 4,484,522, issued to Simeth, discloses a registration system utilizing photo optical sensors and printed register marks on the web. Reference signals from said sensors enable the control logic to issue "advance" or "retard" commands to motors affixed to the print cylinders.
U.S. Pat. No. 4,361,260, issued to Hanlan, discloses a method of press registration wherein three reference sensors are located on the press at the drive motor, the print and die station and at a location along the web. Said web location sensor detects printed indicia and transmits pulse signals to the control logic. Said logic transmits "advance" or "retard" commands to the drive motor.
U.S. Pat. No. 4,351,461, issued to Carlsson, discloses a registration method wherein a driver mechanism engages with transversely preformed crease lines such that the web is advanced a predetermined amount with each rotation of the driver mechanism.
U.S. Pat. No. 4,318,176, issued to Stratton, discloses a method of registration utilizing photo optical sensors to provide reference signals to the control logic. Said sensors detect "live" areas of print in the body of printing on the web. The control logic establishes a window of reference signals enabling the logic to modify web "advance" or "retard".
U.S. Pat. No. 4,316,566, issued to Arleth, discloses a registration method for a pouch making machine wherein an encoder is affixed to sealer bar lands, thereby providing reference signals to control logic to aid in providing stepping pulses to the pull roll stepper motor.
U.S. Pat. No. 4,264,957, issued to Pautzke, discloses a method of maintaining web registration wherein a reference signal from sensors detecting printed marks on the web provides data to the control logic, said control logic issuing commands to a compensating device to vary the distance between adjoining print stations.
U.S. Pat. No. 4,214,524, issued to Corse, discloses a method of press registration wherein the control logic, having received appropriate pulse signals from photo optic sensors detecting printed marks, issues commands to web tensioning devices to increase or decrease the amount of pressure exerted upon said web.
U.S. Pat. No. 4,081,944, issued to Sjostrand, discloses a method for reading printed marks on a web by use of photo optical sensors.
U.S. Pat. No. 3,899,946, issued to Niepmann, discloses a method of feeding a print referenced web by way of a web feeding drum of different circumference than the print repeat length.
U.S. Pat. No. 3,806,012, issued to Roch, discloses a method of maintaining print registration by mechanically altering the tension or elongation of the web between print stations.
U.S. Pat. No. 3,774,016, issued to Sterns, discloses a method of registration wherein sensors detect discrepancies between printed marks on the web and severing cuts placed thereon.
The focus of the prior art has been to address the issue of registering one printing plate to another, and each printing plate to die cutting tools and other finishing tools. However, due to serious deficiencies in the current methods of delivering and removing a steady and reliable flow of web material to and from the print and die stations, proper registration is much more difficult to achieve than merely monitoring and controlling the position of each printing plate or finishing tool, on to another.
Many current press designs incorporate the use of a main drive shaft which is geared to print cylinders, nip rollers, dies, and other finishing tools. The disadvantages and registration problems associated with geared systems are previously described. Other press designs utilize stepper or servo motors to vary the rate of rotation at nip, print, and die stations. However, these designs accept web movement as a given. Rather than attempt to control web movement, the prior art has concentrated on registering printing and die operations by advancing or retarding individual shaft rotations to "catch" the moving target area.
The concept of accepting web movement as a given is the key fault in the Indramat approach described previously. The key differences between the Indramat approach and the present invention is that the present invention attempts to minimize web movement. The present invention incorporates a multitude of monitors and controls to eliminate the major causes of web movement. In addition, since there will always be some minor web movement through the press due to stretch and moisture accumulation, the present invention provides for constant monitoring of the web at each print station to allow the motion control logic to correct for these minor web variances when they occur. This is in sharp contrast to the Indramat system which monitors and controls only the position of the individual servo motors without regard to exact web position or movement. Web stretch and lateral web movement caused by air pressure fluctuations in a turn bar assembly cannot be detected by the Indramat system and will proceed unnoticed by the motion control logic. Thus, each printing station may operate in total registration one to another, while being out of synchronization with the web. This is a serious deficiency.
Even more important than gear deficiencies described previously, is the fact that the prior art consistently provides for the pulling of web material from the feed roll. In addition, rewind rolls of material are driven independently of the main press drive shaft.
Press material delivery systems are designed to pull material off the feed roll at the speed of the press. Unfortunately, inertial and geometric forces make this a difficult, if not impossible task, without added braking, tension, and dancer systems.
Unwind roll braking systems described in the prior art typically employ a follower roller attached to an arm. The follower roller rides along the circumference of the feed roll and travels in an arc toward the core as the roll size is diminished. The follower arm pivot is attached to either variable resistance or encoder sensors that provide a steady stream of input signals to the braking system. Thus, the follower roller assembly constantly monitors the roll radius and thereby the outer diameter and circumference of the feed roll and, at full roll radius, signals the braking system to provide maximum hold back tension to counteract the pulling force of the press material delivery system and maintain proper press web tension. Without such hold back, the steady pulling forces of the press material delivery system (pull or nip rolls) would overcome the high inertial forces of a full feed roll, and being of large diameter and significant weight, the full feed roll would dispense large amounts of material at an accelerating rate of flow into the press. If press speed were to be rapidly decreased, the feed roll would continue to free wheel, unwinding unneeded material onto the pressroom floor, until such time as friction and inertial forces bring the feed roll to rest. Thus, the purpose of feed roll braking at full diameter is to prevent excess material from unwinding from the roll and upsetting web tension.
A significant problem with current state of the art press feed systems is evidenced when an out of round feed roll is placed in the unwind station. The out of round condition acts like a cam to force the follower roll in repeated thrusts away from the feed roll, instantly applying additional hold back, only to remove it a second later. No tension control system can cope with such tremendous shocks to the web. Web shifts are drastic, most often resulting in the scrapping of Otherwise good feed rolls.
In a further example of the inherent deficiencies of monitoring only the servo motor shaft positioning of the infeed roll, even an intelligent servo motor, depicted by the Indramat system, driving an out of round infeed roll of web material would be unable to detect the varying rates of material payout due to the out of round condition. Instructing the infeed roll servo motor to rotate at a fixed rate of rotation, while ignoring an out of round condition, will result in erratic feed rates. Thus, web tension would vary with each rotation of the infeed roll causing registration problems from print station to print station.
The infeed servo motor is similarly unable to detect a change in wind tension of the infeed roll. The number of turns of material on an infeed roll varies directly with the wind tension of that roll. Wind tension is rarely consistent throughout a roll. These variances within the feed roll cannot be detected by monitoring shaft position systems.
The irony is that out of round conditions are most apt to occur in large diameter rolls, due to their weight and the increased occurrence of dropping such large rolls. It is just such large rolls that result in the most dramatic shock jolts to the web when the follower encounters the out of round portion of the roll. No suitable solution has been presented for this problem by the state of the art.
As the feed roll diminishes in radius, the follower roller descends toward the core, signaling the brake to apply a rapidly diminishing amount of hold back, until such point, at approximately one fourth of initial roll size, where hold back is discontinued entirely. Hold back is not necessary at smaller feed roll diameters because each rotation of the reduced circumference feed roll delivers a steadily decreasing length of material to the press. The challenge then, as the feed roll decreases in radius, is to enable the feed roll to rotate at a rate fast enough to dispense an adequate amount of material to the press. At high press speeds, such high feed rotations are almost impossible to achieve.
The Indramat system described previously provides for a an infeed unwind system that is powered by a servo motor, thus eliminating the problems of pulling material off of the infeed roll. The underlying assumption in this approach is that if infeed roll revolutions can be monitored and controlled by the infeed servo motor shaft, dancer rolls can take up any minor variations in infeed roll payout.
As previously described, infeed material delivery problems such as out of round rolls, varying tensions within the infeed roll, and material stretch all contribute to web movement. Meanwhile, at the opposite end of the printing press, the same inertial and geometric forces affect the process of rewinding the finished printed and die cut material onto a final roll. While the press is operating, and the full feed roll is receiving maximum hold back forces by the braking system on the feed end of the press, the rewind, being at minimum diameter, is at maximum torque.
FIG. 1b depicts a rewind tension chart that demonstrates the preferred rewind methods and suggested taper tension rates for different types of web materials. One should note that the chart prefers that all papers, (such as those used to manufacture envelopes and business forms) and laminates are to be rewound at a tapering rate ranging from 1.5:1 to 2:1. Thus, for a taper of 2:1, the start of the rewind roll begins at a winding tension of two pounds tension per linear inch and proceeds to taper off to one pound per linear inch as the roll diameter increases, exactly the opposite of the feed roll.
At the beginning of the press run, the full unwind roll is receiving maximum hold back force while, at the same time, the rewind roll is attempting to advance the rewind roll at maximum force. These opposing forces exert maximum stress on the web, resulting in stretching and breaking. Add to these preexisting stresses the stretching resulting from moisture accumulation the web may acquire by way of the printing process, i.e., ink, ink solvents, drying agents, and plate wetting agents such as water and alcohol, etc. As the printing operation progresses toward mid roll, the feed roll hold back diminishes and the rewind advance begins to taper off. Thus, overall web tension decreases and whatever adjustments the press operator made at the outset of the printing operation are now rendered obsolete. Therefore, the press is in need of additional adjustments.
As the feed roll nears the core, the feed roll, being of small diameter and low weight, exhibits little, if any, inertial force. In addition, the drastically reduced roll diameter results in a condition where the feed roll can no longer rotate at a speed fast enough to dispense a proper length of material to the press. These two factors cause increasing web tension at the feed end of the press, the press being starved for material feed. The press operator can reduce the speed of the press, but that would disrupt registration, requiring added adjustments at a point when material is about to run out but this is not a wise operational choice.
At the rewind end of the press, the rewind roll is reaching maximum diameter and receiving a minimum amount of advance tension. In a conventional printing press, neither feed roll hold back, nor rewind advance is controlled by the main drive shaft of the press. Unwind braking systems operate independently of the main drive shaft. Rewind systems incorporate a motor independent of the main press motor, the rate of rotation of which is a ratio higher than that of the main motor of the press. Thus, the rewind motor is always rotating faster than the rate of the press. The rewind rate of rotation and taper therefore is controlled by either a mechanical or air controlled clutch device.
In summary, extreme tension is present at the beginning of the printing process, with the feed roll preferring a state of hold back, while the rewind roll prefers a state of advance. The printing process proceeds to a neutral state at midroll, where hold back and rewind advance are approximately equal. Then, toward the end of the feed roll, press conditions shift to a state where a disproportionate amount of tension is at the front end of the press at the feed roll. If the opposing forces of unwind hold back and rewind advance were exactly equal, only web tension would be affected by the state of roll diameter, not that of web position.
In practice, however, hold back and rewind tensions are never exactly equal. When unwind hold back is greater than rewind advance, the web shifts toward the feed roll. If the press operator applies an excess amount of air pressure to the rewind clutch assembly, the opposite condition will occur, where rewind advance exceeds the unwind hold back, resulting in the web shifting toward the rewind end of the press. The press operator can either decrease unwind hold back or increase rewind advance to correct such web shift. However, as the operation proceeds toward the end of the feed roll, even the total elimination of unwind hold back cannot stop the increasing tensions and the ultimate shift of the web toward the unwind end of the press. The press operator can increase the amount of rewind advance to counteract the web shift. But such an increase in rewind advance tends to apply greater tension to the previously loosened circumferential windings on the rewind roll, resulting in the lateral shifting of such windings in a cone shaped pattern known to those skilled in the art as "telescoping". If the press operator does not immediately detect such telescoping, the rewind material will shift laterally to the point where it will disengage from the circumference of the rewind roll. Once disengaged from the outer circumference of the rewind roll, the printed and die cut material will proceed to wrap itself around the rewind driving shaft adjacent to the full roll of rewound material, thereby starting a second roll of rewound material and again changing web tensions.
Thus, as mentioned earlier, press tensions, and therefore web positioning, are constantly changing. Current press designs incorporate a tension transducer to detect changing web tensions and a dancer assembly to absorb the web shock from changing web tensions, or, in the alternative, to force a change in web tensions or web positioning. Other attempts have been made to monitor and control infeed roll shaft rotation. However, none of these devices correct the cause of web shifts, namely, high initial inertial roll forces requiring hold back, low inertial forces at roll end, material starvation at the end of the feed roll, out of round conditions, varying tensions within the infeed roll, material stretch, and tapering rewind tensions. Nor can the current state of the art as demonstrated by the Indramat system, by monitoring and controlling only servo shaft position, detect movements within the web or tension changes within the press. The mechanical gear systems only deal with the problems caused by the independent systems of unwind hold back and rewind advance, and their relationship to the material delivery systems of the press.
In addition to the stretching forces inflicted onto a web by the infeed and rewind inconsistencies already discussed, web movement variations are influenced by speed of the web, the amount of inks and coatings applied to the web and the accompanying absorptive capacity of the web material in conjunction with the relative humidity of the production environment, rate of solvent evaporation from the inks and coatings, and temperature and air velocity of the drying devices.
Web materials have a tendency to accumulate and retain heat through each successive pass through a print station dryer, resulting in web stretch and breakage. The same is true with each additional application of printing inks and coatings. Thus, it is especially important to monitor the temperature and moisture content of the moving web after the web material passes through each drying station.
Commonly accepted practice in the industry is to apply heated air to the web after each print or coating operation. It is also common industry practice to increase the temperature of this heated air to speed drying. In many cases this practice is counter productive. As previously mentioned, heat buildup on the web is common. After the web has been heated beyond optimal temperature, additional heat applications will actually prevent ink adhesion to the web.
This phenomenon occurs because the superheated web material immediately vaporizes the ink or coating solvents as they first come in contact with the web. The first film of ink or coating that comes in contact with the heated web dries immediately, before it has a chance to penetrate the web, and in effect seals the web against further ink or coating penetration. In addition, the drying solvents that were present in this initial ink or coating film application are driven away from the web into the still liquid layer above it, adding to the solvent content of the remaining ink or coating material resting on the surface of the web.
At this point press operators routinely raise the temperature of the heated air even further to force solvent evaporation from this stagnant ink or coating film. This is also counter productive. With web heat forcing solvents away from the web, and additional heat air being directed at the opposite film edge of the ink or coating, the result is rapid solvent evaporation from the outer film edge of the ink or coating. This causes the ink or coating to "skin over" forming a liquid center between the skin and the web.
An analogy to this phenomenon can be found when painting a house. If paint is applied on a dry sunny day to superheated wood siding, the bottom layer of paint dries almost on contact with the surface. If the painter were then to use a heated air dryer on the outer surface of the paint, it would "skin over", leaving a still liquid center trapped in between the wood siding and the surface skin. This is the reason paint manufacturers do not recommend applying paint onto a heated surface.
By monitoring web temperature and moisture content after each pass through the dryer that present invention can eliminate web superheating by varying the temperature and air velocity present in each dryer. In fact, successive dryers can actually cool the web to prevent overheating. If increased air temperatures do not result in lowered moisture content readings, increased air velocity is indicated in order to break the solvent vapor barrier away from the ink or coating surface.
Two sided printing is not easily accomplished on a flexographic, rotary letterpress, or rotogravure printing press. Unlike an offset printing press, where ink is "offset" from a lithographic plate to a smooth rubber "blanket" and then to the web, flexographic and rotary letterpress technologies transfer ink directly from the raised surfaces of the printing plate to the web material. Thus, each printing plate must have stable support (impression cylinder) under the web material in order to achieve a satisfactory ink transfer. Rotogravure is similar in its transfer of ink directly from the plate to the sheet or web material. However, in rotogravure printing the ink is deposited into recesses in the printing cylinder, rather than on raised surfaces. The rotogravure printing process requires the web to be squeezed into the printing cylinder at higher pressures in order to transfer the ink to the web.
Two sided printing without a turn bar is common in the offset printing industry. In a "perfecting" offset printing press two printing stations, top and bottom, are arranged opposing each other, most often in a vertical arrangement, with the web flowing between the two opposing print stations. As ink is transferred (offset) from plate to blanket and then to the web, the web is actually squeezed between two smooth blankets, each rotating at the same speed, each acting as the other's impression cylinder.
The same method cannot be utilized in flexographic, rotary letterpress, or rotogravure because the plate is the vehicle that transfers the ink to the web and the plate contains either raised or recessed areas. Squeezing the web between two opposing flexographic plates, for example, would result in web creases, ink distortions, and web perforation. The state of the art for flexographic, rotary letterpress, and rotogravure printing presses has mandated the use of a turn around device to rotate the web radially 180.degree.. The disadvantages to the turn around device have been discussed previously.
U.S. Pat. No. 4,917,010, issued to Gilham describes a franking machine with a variable and fixed date thermal printhead. The described thermal printer is designed with heating elements assembled in line arrays to print either characters, numerals or a combination of both. The Gilham printer as described cannot print graphics or bar codes. Gilham discloses a matrix of dot printing elements individually selectable to print a desired character or other pattern. Gilham's provision of arrays of elements either in the form of strips or dots for printing characters provides a speed advantage over a thermal printer using a single thermal strip for selectively printing a row of dots and which requires sequential operation to build up the characters.
The key to producing sharp, aesthetically pleasing and scannable variable information is to use a thermal head with the highest possible density of microdot heaters. The optional thermal heater, as described by Gilham, would be prohibitively expensive, being on the order of $5,000-10,000. As a practical matter, the standard array that Gilham mentions is not a workable design for imprinting envelopes with variable information, bar codes and graphics. Gilham makes no mention of a feed device for either the envelopes or the film ribbon. Gilham's design, as disclosed, would not work with envelopes or boxes as disclosed in the present invention. Most thermal printers advance the substrate material by way of a drive roller mounted directly under the print head. The drive roller is driven by a stepper motor that is interconnected to a printer "driver" circuit board. The main disadvantage to such an approach is that the device wastes a length of thermal ribbon equal to the length of the length of the driven substrate material. If the envelope is for example, 6" in length, such a device will consume 6" of ribbon.
Other "ribbon saver" devices are available from suppliers such as Zebra Technologies Corporation, 3455 Commercial Avenue, Northbrook, Ill. 60062. In these ribbon saving devices a friction feed rubber roller doubles as both an impression cylinder and a drive roller. This roller is raised toward the thermal print head during print operations and rotates to advance both the business form and the thermal transfer ribbon. As the business form approaches areas where printing is not desired, the rubber impression cylinder is lowered, while a second friction feed device, located downstream from the print station area, powers the advancement of the form while the thermal transfer ribbon advance is halted.
In an alternative design, only one friction feed roller is employed, located downstream from the print station. The impression cylinder, located directly below the thermal print head, is merely raised and lowered according to the print, no print commands from the device's logic. In this design, the thermal transfer ribbon is advanced by relying on the adhesive characteristics of ink itself. Because the surface tension of this wax like ink is relatively low, feed tension of the thermal ribbon must also be low, or stretching of the thermal ribbon will result. This is a significant disadvantage.
Another disadvantage of relying on surface tension to advance the thermal ribbon is the high incidence of creased thermal ribbon resulting in broken printed characters and skewed printing. This is caused when the graphics or text being printed by the thermal print head are not balanced across the business form.
For example, a 4" wide form is advanced through a thermal print head, with heavy ink coverage being applied along a 1" edge of the form. As the thermal ink along this edge is melted onto the form by the heaters in the thermal print head, the ribbon tends to adhere to the form only in that area. However, the 3" of ribbon adjacent to this 1" band of printing is not adhesively attached to the form. When the rubber impression roller is lowered to halt ribbon advancement, and the form alone is advanced by the friction roller downstream from the print area, the thermal ribbon travels along with the form for a short distance until it reaches the peel bar, where it is detached from the form. During that small amount of travel, a disproportionate amount of stress is applied to the 1" area where printing was accomplished. No pulling action is generated in the 3" area where no printing was performed. Thus, the ribbon tends to wrinkle due to the uneven stress.
Both of the aforementioned designs rely on friction feed advance mechanisms. These mechanisms have inherent drawbacks due to their tendency to slip. Slippage can be due to several factors. First, coated paper stocks tend, with sustained use, to impart a calendared finish to the rubber friction feed roller, causing slippage. Second, since thermal transfer ribbon actually transfers a wax like ink substance to the top of the business form, and since heat is the vehicle that accomplishes this transfer, insufficient cooling may result in a buildup of thermal transfer ink onto the rubber friction feed roller. This not only can result in slippage, but in ink transfer from the roller to the face of subsequent forms, causing ghosting images.
An additional problem encountered in the box making field when using a continuous machine moving at relatively high speed is a method of synchronizing or at least accounting for variations in line speed at various points during the manufacturing process.
U.S. Pat. No. 5,041,070, issued to Blaser, discloses the use of a magnetic sensor, a stepper motor, and a logic control unit. However, Blaser uses these devices to feed material on an intermittent basis. The web is fed intermittently through the bag machine with a short dwell period during which the seal bar unit is actuated to seal and sever the web. The Blaser reference does not contemplate continuous web movement. The very nature of Blaser's process prohibits the continuous advancement of the secondary web. For example, the feed rolls are rotated to advance the web a distance equal to the length of the finished bag. Rotation of the feed rolls is thus synchronized with the movement of the seal bar to move the web only within the rest period of the seal bar, that is, with the seal bar in the raised position.
U.S. Pat. No. 4,545,780 discloses a carton erecting apparatus which includes an accumulator area for the preprinted web material.
An additional problem in assembly line envelope addressing and stuffing is the handling of invoices or statements, multiple advertising inserts, and return envelopes and coupons. For example, credit card companies, department stores, business firms, non-profit organizations and those engaged in direct mail response activities have long utilized a method of packing a return response envelope in the same mailing envelope that contains the invoice, monthly statement or direct mail advertisement. As to monthly invoices or statements, it is also common practice to enclose secondary literature to impart knowledge to the receiving party, or to further entice them with advertisements.
To eliminate the tedious task of matching the personalized invoices, statements, or advertisements to a matching preaddressed mailing envelope, most sending organizations use a window envelope. The personalized matter they send is purposely designed and imprinted in such a manner so that the mailing address aligns with the envelope window when the materials are inserted. The printed materials are also purposely designed so that a portion of the mailed materials containing information such as the recipient's name, address or account number may be detached from the perforations and enclosed in the supplied return envelope to accompany the recipient's payment or order. The return of this personalized payment coupon is essential for the proper crediting of the recipient's account.
The state of the art teaches that the personalized encoding of the return reply envelope is impractical due to the fact that personalized invoices are generated in large batches and stuffed into a window envelope, along with a pre-addressed but not personalized return reply envelope. If the sending organization were to print personalized return reply envelopes, they would then have to exactly match each personalized return reply envelope to its corresponding invoice. Any mistake in the matching process would result in the miscrediting of payments to the wrong accounts. The typical sending organization would not want to take that chance.
When there is only a single return mailing site for payment or order processing, the sending organization often encloses an ordinary style envelope that is pre-printed with the desired return mailing address. The recipient encloses the detached portion of the sender's mailing in the supplied envelope, seals it, affixes postage, and mails it. When the sending organization utilizes multiple return mail acceptance sites, as is most often the case with credit card companies and nationwide department stores, the return envelope is a window style. In that instance, the detached portion is also designed so that the preprinted return mailing address of the nearest regional payment or order processing center aligns with the envelope window.
In order to accurately locate the mailing address within the window area of both the sending and return envelope, the sending organization is usually forced to design the mailing materials to include two distinctly different information panels. One panel contains the recipient's mailing address, while the other detachable panel contains the sender's return address. Due to minimum envelope size requirements by the U.S. Post Office, these two panels most often each correspond to a size of 31/2".times.the envelope width.
Except for the necessity of locating the mailing address within the envelope window area, there is no other reason for these panels to be so large. Also, for identification purposes, the sending organization usually desires that some part of the original mailing be returned with either the customer's payment or their purchase order, regardless of the style of the return envelope. Ideally, the need for the returned portion can be eliminated entirely.
As postal rates have increased, sending organizations have come under intense pressure to reduce the cost of their mailings, to increase the response rate of their direct mailing advertisements, and to reduce the cost of handling the return payments and orders generated by the original mailing. This has caused sending organizations to utilize every available opportunity to entice their customers to buy, making it commonplace for them to enclose advertising and promotional material with their monthly invoices and statements.
In order to increase the response rates of these mailings, sending organizations have increasingly applied promotional and motivational messages to the front of the envelope. Some sending organizations apply printed pressure sensitive labels containing the message to the front of the envelope, while others actually print the message on the front of the envelopes using conventional envelope printing techniques.
Another cost saving technique available to sending organizations is the discount postage offering of "ZIP+4", available from the U.S. Post Office. To qualify for this discount, sending organizations must include the entire 9 digit zip code in the address portion of the envelope. To ensure more rapid processing and possibly a greater discount in the future, the sending organization can apply the U.S. Post Office "POSTNET" "ZIP+4" bar code along the bottom edge of the envelope. Some sending organizations have availed themselves of the advantages of POSTNET ZIP+4 by bar coding the bottom edge of the invoice, statement, or advertisement address panel and by using an envelope with two windows, one for the alphanumeric address, and a second window along the bottom edge for the ZIP+4 bar code.
Unfortunately double-window envelopes add even more cost to the mailing. And, because automated postal equipment grips the envelope along the delicate windowed bottom edge, wrinkling, tearing, and contents damage can occur. This is a distinct disadvantage because envelope appearance is of prime concern to sending organizations.
Preprinting the bar coded ZIP+4 on a single window envelope is even more troublesome, as it defeats the purpose of using window envelopes in the first place, since it once again requires the sending organization to match the contents to the envelope. Printing the ZIP+4 on the envelope after it has been stuffed would require the sending organization to hand enter the zip code (a time consuming process), scan the human readable zip code showing through the window, or carefully track the order of stuffed envelopes as they enter the bar code printer.
Sending organizations encounter yet another problem when stuffing return envelopes into the mailing envelope along with other printed advertising materials. In many cases the consumer removes the entire contents of the envelope, keeping only the relevant personalized matter and discarding the rest-including the return envelope. Then, when returning a payment check or purchase order, the consumer is forced to provide yet another envelope and hand address it. The random sized envelopes consumers send back must be hand processed upon their receipt by the sending organization. The present invention eliminates the use of loose return reply envelopes and instead provides for the retention and use of the envelope by attaching it directly to the invoice itself. The recipient must physically remove the envelope from the invoice, thus eliminating the discarding of loose return reply envelopes.
In addition to these problems, the environmental consequences of massive direct mailing has required sending organizations to reexamine their use of windowed envelopes and pressure sensitive promotional and address labels. Current paper recycling technologies cannot process envelopes that contain a translucent glassine or clear plastic film window. And, while the current recycling technologies can remove pressure sensitive adhesives from envelopes, the waste sludge that results from such removal poses disposal problems. Sending organizations in the future must employ mailing strategies that consume less paper and use materials that are fully recyclable.
Numerous variations of envelope designs have been developed to address the above-mentioned problems with billings and direct mailings. For example, U.S. Pat. No. 5,169,060, issued to Tighe, et. al, discloses a direct and return mailing unit consisting of a pouch attached to intermediate connected panels of printed matter, such intermediate panels being of lesser longitudinal dimensions than said pouch and one said panel containing a die cut window for address purposes. Upon completion of imprinting, said panels are folded successively upon each previous panel and sealed by adhesive means to said pouch, thus forming a mailing device with open sides. The Tighe invention may be opened using conventional means. However, the improper insertion of the letter opener will sever the flap from the return envelope, rendering it useless.
U.S. Pat. No. 5,161,735, issued to Bendel, discloses a self-contained insert mailer, consisting of three mailer panels, each constructed of five plies of material, wherein the front ply includes image transfer means for transferring an image printed on said front ply to the back ply. The mailer piece is personalized by means of a ribbonless impact printer striking the outermost ply and thereby transferring the personalized data to the relevant inner plies.
U.S. Pat. No. 4,984,733, issued to Dunn, discloses a dual mailer construction intended to accomplish the same dissemination of material that would normally require two or more mailings.
U.S. Pat. No. 4,944,449, and U.S. Pat. No. 4,944,450, both issued to Schmidt, disclose an oversize laser mailer and return envelope, wherein a sheet is folded transversely to form an envelope. The mailer is folded along crease marks and lines of weakness and adhesively assembled subsequent to imprinting.
U.S. Pat. No. 4,934,536, issued to Mills, discloses a series of interconnected tractor-feed envelope pouches, each with an integral pull tab and insert material. In use, the pouch is imprinted in a manner similar to U.S. Pat. No. 5,161,735, wherein a ribbonless impact printer strikes the surface of the outer ply, thereby imparting an image to the inner plies via a carbon or carbonless coating.
U.S. Pat. No. 4,915,287, issued to Yolk, discloses an envelope pouch consisting of three panels and an integral tear-off flap.
U.S. Pat. No. 4,898,322, issued to Coffey et. al., discloses an envelope pouch for use in an automated teller machine consisting of multiple pockets in a single envelope pouch.
U.S. Pat. No. 4,889,278, issued to Steidinger, discloses a printed mailer form, wherein a mailer form is printed and then folded upon itself successively to result in an envelope assembly.
U.S. Pat. No. 4,883,220, issued to Brown, discloses a continuous, partially preprinted, heat sealed envelope pouch for packaging photographic film prior to photofinishing.
U.S. Pat. No. 4,860,945, issued to Breen, discloses a fan-folded envelope pouch with detachable coupon members.
U.S. Pat. No. 4,852,795, issued to Volk, Jr., discloses a mailing cover with reply envelope pouch made from an integral web for insertion into a catalog or magazine.
U.S. Pat. No. 4,852,794, issued to Bennett et al., discloses a direct mail solicitation device consisting of an outer wrapper pouch, a die cut window, an elongated inner sheet and a traditional reply envelope contained therein.
U.S. Pat. No. 4,830,269, issued to Jenkins, discloses a two part mailer with a top opening return envelope pouch, side pull apart opening means on the mailing envelope, die cut window, and an imprintable personalizable inner sheet matching the size of the inner portion of the mailing envelope pouch.
U.S. Pat. No. 4,804,135, issued to Bourbeau, discloses continuous strip envelopes. The Bourbeau invention consists of a web which is die cut with side panels which are to be folded inwardly along fold lines. The next step in the manufacturing process involves folding a back panel upwardly and along a fold line to overlie a front panel and the previously folded side panels. The folding process depicted cannot be accomplished on a traditional web press without substantial modifications, such modifications requiring that the press feed rate be approximately doubled at the finishing end of the press to allow for the feeding of additional material to allow the back panel to be folded onto front panel. The Bourbeau invention does not disclose a requirement for such press modifications, nor does the invention disclose the precise method for performing these successive folding operations on the press, or in the alternative, the requirement that the folding operations are to be performed in separate and subsequent finishing operations.
U.S. Pat. No. 4,776,510, issued to Jenkins, discloses a two part mailer with a mailing envelope pouch containing a glassine window and a traditional return reply envelope adhesively attached to inner printed matter.
U.S. Pat. No. 4,770,337, issued to Leibe, discloses a multiple part business form containing envelope pouches, die cut windows, and personalizable inner matter for imprinting via carbon or carbonless impact methods. The envelope mailing pouch is opened utilizing a side pull tab.
U.S. Pat. No 4,747,535, issued to Haase et al. discloses an envelope assembly wherein the envelope flap is folded onto the face of the mailing pouch. The mailing pouch is formed with by depositing a U shaped pattern of adhesive onto a web in a manner similar to other such pouch designs. Instructions are printed on the pouch face instructing the recipient to grasp a corner pull tab area and lift said flap upwardly and in the direction of a printed directional arrow. The recipient may use the mailing pouch as a return reply vehicle only if the recipient does not mistakenly employ the use of a standard letter opener, in which case the return reply feature is destroyed upon initial opening.
U.S. Pat. No. 4,705,298, issued to Van Malderghem et al., discloses a continuous business form containing a die cut window, a reply envelope and a self imaging web activated by impact printing methods.
U.S. Pat. No. 4,754,915, issued to Steidinger, discloses a mailer form, wherein a single sheet is folded successively, and is openable by a side tear off stub.
U.S. Pat. No. 4,668,211, issued to Lubotta, discloses a method for preparing a returnable self mailer, wherein a single sheet is imprinted and folded upon itself to form an envelope pouch and die cut window.
U.S. Pat. No. 4,651,920, issued to Stenner, discloses a continuous series of panels, wherein said panels are folded transversely to form envelope pouches, in which reply pouch contains a plurality of apertures which allow examination thereof to determine the presence or absence of a particular reply device in a particular pocket.
U.S. Pat. No. 4,632,427, issued to Angus, discloses a combined mailer and return envelope pouch, consisting of die cut address windows and detachable envelope pouch portions. Said envelope mailing pouch is opened by tearing along a longitudinal line of weakness located on the face of said envelope. The inner printed matter is imaged by the use of an impact printing device.
U.S. Pat. No. 4,543,082, issued to Stenner, discloses an envelope wherein panels are folded transversely to form envelope pouches with pockets and apertures, similar to U.S. Pat. No. 4,651,920, also issued to Stenner.
U.S. Pat. No. 4,454,980, issued to Poehler, discloses a return biller envelope book wherein ordinary envelopes are removably affixed to a continuous prefolded web.
U.S. Pat. No. 4,440,341, issued to Pennook, discloses a return envelope mailer consisting of an outer mailing pouch with a side opening pull apart grasping area, and internal informational materials which are the same dimension as the return envelope pouch.
U.S. Pat. No. 4,437,852, issued to Volk, Jr. et. al., discloses a mailer, wherein enclosure sheet(s) containing an adhesively attached return envelope pouch are folded into an outer mailer pouch.
U.S. Pat. No. 4,157,759, issued to Dicker, discloses a continuous mailer with a removable tab portion along the top or bottom edge of the back ply.
U.S. Pat. No. 4,148,430, issued to Drake, discloses a mailing envelope containing personalized inner sheets and a return reply envelope. The outer mailing envelope and the return reply envelope contain die cut windows. The personalized imprinting is accomplished prior to final folding and gluing.
U.S. Pat. No. 4,081,127, issued to Steidinger, discloses a mailer device with an enclosed and separate return reply envelope.
U.S. Pat. No. 4,066,206, issued to Peterson, discloses a continuous envelope assembly. The Peterson invention uses a fold around side design. However, the Peterson invention forms the side fold around feature by way of folding excess material from the face of the envelope/pouch onto the back portion. The Peterson invention entails the waste of material when the envelope is interspaced with business forms. The envelope bottom in the Peterson invention is formed by adhesively attaching the back side onto an adhesive strip. Thus the Peterson invention is a cross between an envelope with full width from side to side, and a pouch which does not have full top to bottom access and must be oversized to allow for its glued seam. The Peterson invention does not disclose the method by which the back side is placed onto a moving web in the exact location required so that the trailing edge is aligned precisely with the adhesive strip.
U.S. Pat. No. 4,011,985, issues to Simson, discloses an advertising device, containing imprinted matter and an integral return reply card or envelope.
Finally, U.S. Pat. No. 3,941,309, issued to Gendron, discloses a combined brochure and return envelope for nonmailing usage, such as a newspaper or handout.